Refrigeration apparatus



Oct. 21, 1942.-

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REFRIGERATION APPARATUS Filed July 24, 1959 WITNESSES: INVENTOR CARLA, F. Abs/N6.

' ATTOR Patented Oct. 27, 1942 REFRIGERATION APPARATUS Carl F. Alsing, North Wilbraham, Mass, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pin, a corporation of Pennsylvania Application July 24,1939, Serial no. 286,218

6 Claims.

This invention relates to mechanical refrigerating apparatus and more especially to a means for cooling and for reducing the vaporization of liquid refrigerant in a capillary flow impedance device.

Capillary tubes forming a passage of relatively small diameter and great length are used in mechanical refrigerating apparatus to maintain a pressure diiferential between the condenser and the evaporator. Such tubes are subject to are.- Irigeration loss due to the fact that the pressure in the tube at the evaporator end thereof is nearly at thepressure of the evaporator and that some of the refrigerant in the tube will vaporize at this low pressure unless the tube is cooled. The liquid refrigerant enters the tube at the temperature of the condenser and, therefore, is quite warm. Considerable heat must consequently be removed from the refrigerant liquid in the capillary tube to reduce vaporization therein to reasonable values. One way of accomplishing this result is to place the capillary tube in heat exchange relationship with the suction tube which connects the evaporator and the compressor. The cooling eflfect of the suction tube on the capillary tube, however, is limited.

One object of this invention, therefore, is to cool the capillary tube by means other than or in addition to the refrigerantin the suction tube.

Another object of the invention is to utilize the cooling means used in cooling the condenser for cooling the capillary tube.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing and forming a part of I this application, in which:

Fig. 1 is a front elevation of the device for cooling both the condenser and the capillary tube;

Fig. 2 is an end elevation of the device of Fig. 1; Fig. 3 is a schematic drawing of the refrigerating apparatus in which the cooling device of this invention is incorporated; and

tubing I5 is bent sinuously and is secured to one edge of a series of parallel and spaced apart metal plates ll between which air is drawn by a fan l8- to cool the tubing 15. The condensed and liquefied refrigerant passes through a screening device l9 at the lower end or the tubing 15 and then passes through a capillary tube 22 which conducts the liquid refrigerant to the bottom of the evaporator H.

A portion 23 of the capillary tube 22 is likewise bent sinuously and is secured to the edges of the metal plates 1! lying opposite the edges to which the tubing i5 is secured.

The fan i8 is driven by a motor 24 and the compressor M by the motor 26; The motor 26 receives its energy from lines 21 and a switch 28 is included in one of these lines 21 and is adapted to be closed by a sylphon bellows 29 which communicates through a tube 3| with a bulb 32 secured to the evaporator H. The bulb 32 contains a volatile-liquid which vaporizes when the temperature of the evaporator ll exceeds a predetermined point. The pressure of this vapor expands the sylphon bellows 29 and closes the switch 28, thereby starting the refrigerating apparatus. When the refrigerant has reduced the temperature of the evaporator H to the required degree, the

bellows 29 contracts, opens the switch 28, and stops the motor 26-.

The portion 23 of the capillary tube 22 is preferably placed on the edges of the plates I! at which the cooling air enters the cooling device so that the heat of the refrigerant liquid in the portion 23 is reduced substantially to the temperature of the air. A second portion 34 of the capillary tubing 22 may be placed in heat exchange relationship with the suction tube l3 preferably by soldering portion 34 of the capillary tubing 22 to the suction tube l3. This heat exchange further cools the refrigerant liquid in the travel through the evaporator and compresoiz.

Furthermore, by Supp substantially all liquid to the evaporator II, the efliciency of the systan is increased because the compressor 14 pumps substantially only gas which has vaporized in the evaporator and performed useful cooling.

Fig. 4 shows a modification oi the invention in denser tubing 15 by a duct I. The condenser which the portion 23 of the capillary tubing 22 is cooled by cooling fins Ila. Separate cooling fins Ilb are utilized in cooling the condenser tubing [5. The portion 23 of the capillary tubing may also utilize a separate cooling medium from that employed in cooling the condenser.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in' the appended claims.

1. In refrigerating apparatus, the combination of an insulated cabinet, an evaporator for cooling the interior of said cabinet, a compressor for withdrawing vaporized 1 refrigerant from said evaporator,-a suction tube connecting the evaporator and the compressor, a condenser tubing for receiving compressed refrigerant vapor from the compressor, means for conducting" refrigerant liquid from the condenser to the evaporator, said means including a capillary flow impeding tube, cooling fins secured to both said capillary tube and said condenser tubing, and means for conducting a cooling medium along said cooling fins to first contact the portion thereof adjacent the capillary tube and thereafter the portion thereof adjacent the condenser tubing, a portion of said capillary tube and a portion of said suction. tube being in heat exchange relationship.

2. In refrigerating'apparatus, the combination of an insulated cabinet, an evaporator for cooling the interior of said cabinet, a compressor for withdrawing vaporized refrigerant from the evaporator, a condenser for receiving the compressed refrigerant vapor from the compressor, means comprising a conduit having at least a portion of relatively small cross-section and great length for conducting liquid refrigerant from the condenser to the evaporator and impeding the flow of said liquid to maintain a pressure differential between the condenser and the evaporator to cause liquefaction of the refrigerant in the condenser, said conduit being directly connected to the condenser in such a manner that substantially no excess refrigerant liquid is trapped therebetween, means for conducting heat from the exterior surface of said portion of the conduit, and means for effecting a flow of a cooling vfluid other than said refrigerant over said last-named heat conducting means.

3. In refrigerating apparatus, the combination a cooling fluid other than said refrigerant oversaid last-named heat conducting means, and means for effecting heat exchange between a second portion of said conduit and the relatively cool refrigerant vapor withdrawn from the evaporator, said second portion being subsequent to said first portion with respect to the refrigerant -fiowing through the conduit.

4. In refrigerating apparatus, the combination of an insulated cabinet, an evaporator for cooling the interior of said cabinet, a compressor for withdrawing vaporized refrigerant from the evaporator, a condenser comprising a container for receiving compressed refrigerant vapor from the compressor, means forming a passage at least in part of small section and great length for conducting the liquid refrigerant from the condenser to the evaporator and impeding the flow of said liquid to maintain a pressure diflerential between the condenser and the evaporator suflicient to cause liquefaction of the vaporized refrigerant in the condenser, said passage being directly connected ,to the condenser in such a manner that substantially no excess refrigerant liquid is trapped therebetween, means for conducting heat from the exterior surfaces of said passage-forming means and of said container, and means for causing a common cooling medium to how over the last-named means to cool the same.

'5. In refrigerating apparatus, the combination of an insulated cabinet, an evaporator for cooling the interior of said cabinet, a compressor for withdrawing vaporized refrigerant from said evaporator, a condenser for receiving compressed refrigerant vapor from said compressor, said condenser including heat-dissipating fins, means for causing a cooling medium to flow over said fins to cool and liquefy the refrigerant vapor in said condenser, and means for conducting the liquid refrigerant from the condenser to the evaporator, at least a portion of said last-mentioned means comprising a capillary tube, said capillary tube being directly connected to the condenser in such a manner that substantially no excess refrigerant liquid is trapped therebetween, said tube being in heat-exchange relationship with said fins to cool the liquid refrigerant in the capillary tube.

6. In refrigerating apparatus, the combination of an insulated cabinet, an evaporator for cooling the interior of said cabinet, a compressor for withdrawing vaporized refrigerant from said of an insulated cabinet, an evaporator for cooling the interior of said cabinet, a compressor 'for withdrawing vaporized refrigerant from the evaporator, a condenser for receiving the compressed evaporator, a condenser for receiving compressed refrigerant from said compressor, said condenser including a conduit and heat-dissipating fins, means for causing a cooling medium to fiow over said fins to cool and liquefy the refrigerant vapor insaid condenser, and means for conducting the liquid refrigerant from the condenser to the evap-V orator, said mean including a capillary tube in heat-exchange relationship with said fins to cool the liquid refrigerant in the capillary tube, said capillary tube connected to the condenser in such a manner that substantially no excess refrigerant liquid is trapped therebetween, the position of said tube on said fins being in advance of the position of said conduit on said fins with respect to the direction of flow of the cooling CARL F. ALSING. 

